High-speed system for feeding and sealing cartons



March 7, 1961 J. F. KILLION 2,973,608

HIGH-SPEED SYSTEM FOR FEEDING AND SEALING CARTONS Filed Sept. 4, 195" 11 Sheets-Sheet 1 J. F. KlLLlON March 7, 1961 HIGH-SPEED SYSTEM FOR FEEDING AND SEALING CARTONS 11 Sheets-Sheef 2 Filed Sept. 4, 1957 J. F. KlLLlON HIGH- SPEED SYSTEM FOR FEEDING AND SEALING CARTONS Filed Sept. 4, I957 11 Sheets-Sheet 4 March 7, 1961 J. F. KILLION 2,973,603

HIGH-SPEED SYSTEM FOR FEEDING AND SEALING CARTONS Filed Sept. 4, 1957 11 Sheets-Sheet 5 mm iii I314! 1;:3 y i-Lili March 7, 1961 I J. F. KlLLlON HIGH-SPEED SYSTEM FOR FEEDING AND SEALING CARTONS ll Sheets-Sheet 6 Filed Sept. 4, 1957 ,VIZO

J. F. KlLLlON March 7, 1961 HIGH-SPEED SYSTEM FOR FEEDING AND SEALING CARTONS 11 Sheets-Sheet '7 Filed Sept. 4, 1957 DZ: OF

HIGH-SPEED SYSTEM FOR FEEDING AND SEALING CARTONS Filed Sept. 4, 1957 J. F. KILLlON March 7, 1961 11 Sheets-Sheet 8 March 7, 1961 J. F. KlLLlON 2,973,608

HIGH-SPEED SYSTEM FOR FEEDING AND SEALING CARTONS Filed Sept. 4, 1957 11 Sheets-Sheet 9 J. F. KlLLlON March 7, 1961 HIGH-SPEED SYSTEM FOR FEEDING AND SEALING CARTONS Filed Sept. 4, 195'? ll Sheets-Sheet 10 emu mm J. F. KlLLlON March 7, 1961 HIGH-SPEED SYSTEM FOR FEEDING AND SEALING CARTONS ll Sheets-Sheet 11 Filed Sept. 4, 1957 United States Patent O HIGH-SPEED SYSTEM FOR FEEDING AND SEALING CARTONS John F. Killian, Philadelphia, Pa., assignor, by mesnc assignments, to Food Machinery and Chemical Corporation, San Jose, Calif., a corporation of Delaware Filed Sept. 4, 1957, Ser. No. 682,042

28 Claims. (Cl. 53-38) This invention relates to systems in which cartons in the flat are opened and fed to a filling station and thereafter closed and sealed, and has for an object the provision of improved means for automatically feeding and sealing the cartons at high rates of speed.

The present invention is an improvement on the systems described and claimed in First et al. Patents Nos. 2,293,498 and 2,318,208. The present invention permits operation at substantially higher rates of speed with a normal operating speed corresponding with an output in the order of 400 or more cartons-per minute. Such high operating speeds are obtainable by reason of the novel features included in the present system.

In accordance with the invention, folded cartons are fed at high speed from a stack of cartons in the flat to a carton conveyor. The feeding means brings the stack of flattened cartons so that the front end of the stack is against an abutment adjacent the carton conveyor preparatory to transfer of a carton thereto. A spring-biased tell-tale is engageable with the front end of the stack for detecting the pressure applied to the cartons in the stack and for controlling this pressure within predetermined limits. The folded cartons are adapted to be removed from the stack by suction members and transferred to the carton conveyor. If the cartons were allowed to be continuously advanced in the stack, the cartons would soon become packed very tightly against each other in the stack, and this would prevent their being removed rapidly from the stack by the suction members, once it was desired to feed the cartons again through the machine.

Further in accordance with the invention, after the cartons are on the carton conveyor, the end flaps thereof are preheated prior to being coated with adhesive, the adhesive being of the hot-melt type and being applied to the end flaps with heated applicators.

Further in accordance with the invention, and after the end flaps at both ends of the cartons have been closed and sealed, the cartons are turned through an angle of 90 to bring their short dimension lengthwise of the conveyor to minimize the length of the drying conveyor and to permit reactivation and folding of the Van Buren ears on the cartons. The cartons are turned by a turnaround mechanism which is driven in predetermined timed relation with respect to the carton conveyor and maintains the individual cartons in predetermined spaced relation during the turning operation.

After the cartons have been turned, they pass through a drying conveyor which is adapted to apply pressure to the tops and bottoms of the cartons while a drying medium is directed against the sealed end flaps of the cartons to minimize the drying time for the adhesive.

The present invention is particularly adapted for sealing cartons of the type including the aforesaid Van Buren cars which are adapted to be sealed against the narrow sides of the carton to make the cartons more sift-proof." After the cartonshave been turned through the angle of 90, they are adapted to pass through a reactivating conveyor where the adhesive on the Van Buren cars is reactivated, and the ears thereafter pressed tightly against the sides of the carton where they are maintained while passing through the drying conveyor. The drying conveyor is surrounded by a housing through which the drying medium flows, the drying medium being either hot or cold fluid depending upon the type of adhesive applied to the carton flaps.

For further objects and advantages of the invention and for a more detailed understanding thereof, reference is to be had to the following specification taken in con-' junction with the accompanying drawings, in which:

Fig. 1 is an elevational view of apparatus for feeding, filling and sealing cartons in accordance with the present invention;

Fig. 2 is a top plan view of the apparatus shown in Fig. 1;

Fig. 3 is a fractional perspective view of the cartonfeeding and transfer station of the apparatus shown in Fig. 1;

Fig. 4 is a vertical sectional view of the carton-feeding mechanism and the carton-opening and transfer mechanism;

Fig. 5 is a side elevation of the carton-feeding mechanism taken along the lines 5--5 in Fig. 2;

Fig. 5A is an end elevation of the carton feed pusher device shown in Figs. 1 and 2;

Fig. 6 is a top plan view of Figs. 5 and 7;

Fig. 7 is a side elevation of the carton-opening and transfer mechanism taken along the lines 7-7 of Figs. 2. and 6;

Fig. 8 is a perspective view showing the preheaters for the carton flaps and the glue-applying roll;

Fig. 8A is a sectional view of the preheaters for the carton flaps;

Fig. 9 is a top plan view of a carton turn-around mechanism shown in Fig. 2;

Fig. 10 is a side elevation of the carton turn-around mechanism;

, Fig. 11 is a sectional view taken along the lines 11-11 in Fig. 10;

Fig. 12 is a perspective view of the reactivating conveyor and drying conveyor of the apparatus shown in Figs. 1 and 2;

Figs. 13 and 13A are top plan and end elevation views of a modification of a pressure-applying means for sealing the end flaps and the Van Buren ears on the cartons; and

Fig. 14 is another modification of a pressure-applying means for sealing the end flaps and the Van Buren ears on the cartons.

The apparatus shown in Figs. 1 and 2 is generally of the type disclosed in First et al. Patents Nos. 2,293,498, 2,318,208 and 2,320,581. The cartons are disposed in the fiat in a stack S, Fig. 1. The stack of cartons S is disposed in the carton magazine 10 with the forward carton in the stack being held against an'abutment 11 by pusher 12, the latter engaging the rear of the stack S. The folded cartons are adapted to be removed from the stack S by a suction device 15. The suction device 15 may be of the type disclosed in the aforesaid Patent 2,318,208 and adapted to be provided with a source of suction illustrated by a vacuum pump 16. The new mechanism for controlling the feed and opening of cartons from the stack S is contained within housings 18 and 19, Fig. 2, and will be hereinafter described more in detail. The cartons are removed from the stack and moved against a guide 20, Fig. 3, to assist in opening the cartons from their flattened position, and the open cartons are then pressed into position by a pusher device 21. The cartons C are thus transferred from the stack S to an endless carton conveyor which comprises a plu rality of pairs of blocks ,or similar clamping elements 22 forming pockets in which the cartons C are disposed during their transport extending outwardly from the endle'ss conveyor belt 23, Fig. 3. The moving belt 23 passes around a pair of drums 24, Figs. 1 and 2, and is driven continuously from a synchronous motor 25. One or more guide rails 26, Fig. 8, are disposed along the outer side of the conveyor and assist in holding the carton in the conveyor pockets.

After the cartons C are transferred to the carton conuveyor, the long end flaps C Fig. 3, at the bottom of the carton are adapted to be turned outwardly to a horizontal position by guides 28, Fig. 2, and the short end flaps C Fig. 3, at the bottom of the carton are turned inwardly by a rotating device 29, Figs. 1 and 2. One of the long top end flaps C is then adapted to be marked with a suitable code by a codinng device 30, for example, of a type similar to that disclosed in the aforesaid Patent 2,293,498. The bottom flaps C are then preheated and coated with adhesive by a roller 32 in manner hereinafter described more in detail. The adhesivecoated end flaps C are then turned inwardly by guides 33, and the folds are squared by pressureapplying devices 34, Figs. 1 and 2. After the bottom flaps of the carton C have been coated with adhesive and closed, the flaps are adapted to be held in closed position while the adhesive sets by the endless belt 35 which is disposed beneath the carton conveyor 23.

As the cartons move along on the conveyor 23 at a high rate of speed, they pass through a filling station F which is adapted to fill cartons at a high rate of speed, for example, in the order of 400 to 500 or more cartons per minute. The filling station F preferably includes mechanism of the type described and claimed in copending application, erial No. 681,240, filed August 30, 1957, by Walter E. Flack, a co-employee. Briefly, as the cartons move along on the conveyor 23, they engage a switch 37 which is disposed along their path of movement at a point adjacent a rotary filling head or turret 38. When the switch 37 is closed, the actuator 39 for the product conveyor 40 is energized which starts a controlled flow of product from a supply hopper 41 along the product conveyor 40 so that it passes over an inclined scale pan 42 which is connected with a weighing scale 43. The product passes over the inclined scale pan 42 and into the plurality of funnels 44 which depend from the rotary turret 38. The product passes through the funnels 44 and into the individual cartons C which are positioned beneath the funnels on the continuously moving carton conveyor 23. The motor 25 is adapted to drive both the carton conveyor 23 and the turret 38 at a predetermined uniform speed so that the pockets or funnels 44 will move continuously at the same speed and in synchronism with the cartons which are disposed therebeneath on the carton conveyor belt 23. When the density of the product changes, the position of the scale pan 42 will be raised or lowered accordingly, and this action is transformed into a correspondmg electrical signal which is transmitted to the actuator 39 to increase or decrease the motion of the conveyor 40 as required to maintain a flow of uniform weight of product across the scale pan 42. With the foregoing arrangement, the individual cartons will be filled rapidly and with a uniform weight of product regardless of change in density of the product during the particular run.

After the cartons have been filled with the product at the filling station F and as they continue to be moved along by the endless carton conveyor belt 23, the short end flaps C.,, at the top of the carton C are folded inwardly by a device 50, Fig. 2, and the long end flaps C at the top of the carton are folded outwardly by guides 51, the latter flaps being preheated and coated with adhesive by an adhesive-applying device 52 and thereafter folded over into sealed position by guides 53,

with the folded corners being squared by pressure members 54, Fig. 2. The top end flaps of the carton are held in sealed position by a pair of rods 56, Fig. 9, which extend over the carton conveyor belt 23. The bottom flaps on the carton are held in sealed position by an endless belt 58, Fig. 2, which is driven at the same speed as the car-ton conveyor belt 23. The cartons C are then transferred to the turn-around station T, Fig. 2, where the cartons are turned through an angle of so that they Will proceed broadside through the remainder of the system. The turn-around station T includes mechanism for positively controlling the position and spacing of the cartons while they are being turned through the angle of 90, as later to be described in detail. After the cartons have been turned to their broadside position, they pass through an adhesive reactivating station R and an adhesive drying station D, Fig. 2, as later to be described in detail. Since the cartons are moving through the system at a high rate of speed, it will be appreciated that it is extremely important that the flaps on the cartons be dried as rapidly as possible in order to minimize the length of the drying conveyor.

Having described the complete system in. general, specific portions of the system will now be described in detail. The construction of the carton-feeding and opening mechanism is shown in Figs. 37. Referring to Fig. 4, there is shown a main drive shaft which is driven from the main drive motor 25 by way of a chain 101 on a sprocket 102. The drive shaft 100 is adapted to drive both the carton-feeding mechanism contained in housing 10, and also the carton-opening or transfer mechanism contained in housing 13, Fig. 4, The main shaft 100 at its right-hand end is provided with a sprocket 104 which cooperates with a chain 105 to drive a sprocket 106 which is fixed to an eccentric cam 107 and rotates on a stub shaft 108. As may be seen in Fig. '5, the surface of the eccentric earn 107 is adapted to be engaged by a cam follower shown in the form of a roller 109 mounted on the end of an arm 110 which extends from the one-way clutch 111. The one-way clutch 111 is of the ratchet type and when the arm 110 is rotated in a counterclockwise direction, as shown in Fig. 5, the clutch 111 is effective to drive the sprocket wheel 113 in a corresponding direction and thus advance the chain conveyor 114 for the stack of carton blanks S. As may be seen in Fig. 4, the shaft 112 is provided with a pair of sprocket wheels 113, each adapted to drive a sprocket chain 114 to form the chain conveyor for the carton stack. The chains 114 pass through the bottom of the carton magazine, Fig. .l, and are adapted to drive the carton pusher device 12 toward the left, as viewed in Fig. l.

The carton pusher device, as shown in Fig. 5A, comprises a plate member which is hinged at 121 to a trolley member 122. The trolley member 122 is substantially U-shaped and includes a plurality of rollers 123 which are adapted to engage the flat spaced sides of a guide rail 124 which is mounted along the side of the carton magazine 10, as by brackets 125. The plate 120 is provided with a handle 126 to aid in rotating the plate 120 about the hinge 121 to remove the lugs 120a at the bottom of the plate from engagement with the respective chains 114 for reloading the carton magazine with a new stack of cartons. To aid in guiding the cartons, the plate 120 is provided with a side member 120!) to which the handle 126 is secured, Fig. 5A.

The chains 114 are adapted to pass over guides 127 which are adjustable transversely of the carton magazine 10 to accommodate cartons of dilferent sizes. The magazine 10 is supported on floor stands 128 as shown in Figs. 1 and 5A.

The cartons C are adapted to be removed from the stack S by means of pivoted suction members 15, Fig. 3, and

"in order for these suction members 15 to be able to aez me feed the cartons at high rates of speed, such for example, as 400 or 500 cartons per minute, it is necessary that the pressure of the cartons in thestack S be controlled. If the cartons are pressed too tightly together in the stack, it will hinder their removal by the suction members 15 and thus prevent the machine from obtaining the desired high operating speeds. To this end, there is provided means for automatically controlling the pressure on the cartons C in the stack S in accordance with a predetermined selected pressure. As may be seen in Figs. 4 and 5, there is provided a member 130 which is adapted to be secured to a pair of guide rods 131 and 132. The control member 130 is adapted to be adjustably secured to rod 131, as by a set screw 133. The rods 131 and 132 are adapted to reciprocate in the respective bearing members 134-136 which in turn are secured to the sides of the housing 19. Connected to the outer end of the rod 131 and extending transversely across the end of the stack of cartons S is a feeler or tell-tale member 138, Figs. 5 and 6, which is adapted to engage the outermost carton in the stack. The feel'er 138 is adapted to be urged against the outermost carton by means of a coil compression spring 140 which surrounds the opposite end of rod 131 with one end of the spring 140 in engagement with the adjacent end of the bearing sleeve 135, Fig. 5. The opposite end of the spring 140 is engaged by a collar member 141 which is adjustably secured by a set screw 142 to the rod 131. By adjusting the position of collar 141 lengthwise of the rod 131, the compression on the spring 140 can be controlled in a predetermined manner and this, in turn, will control the pressure applied to the cartons in the stack by the pusher device 12, as nowto be described.

As may be seen in Fig. 5, the spring 140 is adapted to move the rod 131 to the right and thus move the feeler 138 into engagement with the outermost carton in the stack S. This action also is adapted to move the projection 130a on member 130 into engagement with the member 146 carried at the outer end of the clutch arm 110. From the foregoing, it will be seen that the spring 140 is adapted to urge the cam roller 109 against the surface of the eccentric cam 107. When the cam 107 rotates, the high portion of the cam will in turn cause the arm 110 to rotate in a counterclockwise direction about shaft 112, and the spring 140 is adapted to rotate the arm 110 in reverse direction about shaft 112 to return the arm to its original position, preparatory to rotation again in a counterclockwise direction by the eccentric cam 107. The foregoing action takes place as long as the pressure of the carton stack S on the feeler member 138 does not exceed the pressure of the spring 140. As soon as the pressure of the cartons in the stack exceeds the pressure produced by the spring 140, the latter is not effective to return the control member 130 and its projection 130a to the right a sufficient distance to move the cam follower or roller 109 into engagement with the eccentric cam 107. Thus the control member 130 and its projection 130a will be positioned to the left a slight distance from that shown in Fig. 5 with the member 146 at the outer end of the one revolution clutch arm 110 in engagement with projection 130a. The arm 110 of the clutch remains in this position with the eccentric cam 107 continuing to rotate but not engaging the cam follower 109 until a sufficient number of cartons are removed from the stack S to reduce the pressure on the cartons in the stack below the predetermined pressure controlled by the spring 140. When the carton pressure in the stack is reduced below the predetermined value, the spring 140 will again bring the cam follower 109 against the eccentric cam 107 to rotate the arm 110 of the one cycle clutch in a counterclockwise direction'to again advance the feed chains 114 for the carton maga- .zine, thus moving the stack S to the left, as shown in Fig.5.

Iii-order to prevent the spring 140 from continuing to be effective to control advancement of the feed chains- 114, there is provided a solenoid 150 including a plunger or movable element 151 which is connected by way of a lever 152 to the arm of the one cycle clutch. When the solenoid 150 is energized, the member 151 is adapted to hold the arm 110 of the clutch out of engagement with the periphery of the eccentric cam 107 and thus prevent the one cycle clutch 111 from further advancing the conveyor chains 114 and thus maintain the pressure of thecartons in the stack S at the then existing value.

It is sometimes desirable to stop removing cartons from the stack S but to continue the movement of the carton. conveyor 23 so as. to clear the conveyor of all cartons on it at that time. Since the drive shaft 100 continues to be driven with the conveyor 23, the cam 107 will continue to rotate. The highspeed rotation of cam 107 creates a slight cycling action of spring which in turn may cause a slight feed of stack S. To prevent this when cartons are not being removed from the stack, the solenoid is adapted to be energized along with the solenoid 152, Fig. 7, by switch 153 which operates the vacuum valve 154 to conduit 180 so as to cut off suction to the suction members 15 from the vacuum pump 16, Fig. 1, thus locking the arm 110, Fig. 5, and preventing movement of the feed chains 114.

Referring to Figs. 4 and 7, it will be seen that the drive shaft 100 is also adapted to drive the suction transfer members 15, Fig. 7, and the carton pusher 21 which, because of its prongs, issometimes referred to as a devils fork. A sprocket wheel is secured to the left-hand end of drive shaft 100, Fig. 4. The sprocket wheel 160 in turn is secured to the balanced cam 161 which is adapted'to rotate with the sprocket 160 on the drive shaft 100. A sprocket wheel-163 is secured to another balanced cam 164, both of which are adapted for rotation on a stub shaft 165, by way of a sprocket chain 166 which surrounds and interconnects the sprockets Wheels 160 and 163. The balanced cam 161 is provided with a circular cam track 161a which is adapted to receive a cam follower in the form of a roller 168 which is carried by a member 169 secured to a rod 170. The rod 170 is adapted for reciprocation in bearing structure 171, Fig. 7, and the lower end of the member 169 is provided with a guide 169a which is adapted to reciprocate in a slot 18b in housing 18. The rod 170 is connected by way of a bifurcated member 173, pin 174, and link to a pin 176 which extends through an opening in an arm 177 which is secured by a bolt 17 8 to a tubular member 180. The lower end of member 180 is connected as by a nonrotating section 180a and a hose 181 to the suction pump 16. The suction members 15, which are adapted to engage cartons in the stack S, are secured to the tubular member 180 and are adapted for rotation about the axis of the tubular member 180. 'From the foregoing, it will be seen that the rotation of-the tubular member 180, and thus the suction members 15, results from the reciprocation of rod 170 which in turn is produced by the rotation of cam 161 driven from drive shaft 100. The tubular member 180 is provided, as the aforesaid Patent 2,318,- 208, with a relief valve 155 which is in normally closed position and is timed to open when the suction devices 15 have removed a carton from the stack S. The tube 180 is provided with an opening in' the side wall which moves into and out of alignment with the opening 155a in valve 155 to cyclically connect the tube-180 with atmosphere. As mentioned above, when cartons" are not being fed from the stack S, the solenoid valve 154 cuts The device '21 is, connected to, the end of a rod 185 which 7 gee-sees supported for reciprocation in bearing structure 186. Secured to the rod 185 is a member 187 which is provided with a cam follower in the form of a roller 188 Which is. adapted to engage the cam track 164a in the balanced cam 164. The member 187 is also provided with a guide member 190 which is adapted to be received in a slot 180 in the housing 18. Since the balanced cams 161. and 164 are both driven from the main drive shaft100, the suction members and the pusher device 21 will be moved in predetermined timed relation with respect to each other and with respect to rotation of the carton conveyor 23. By providing balanced cams in the drive mechanisms for members 15 and 21, it is possible to feed the cartons at high rates of speed, such for example, in the order of 400 to 500 or more cartons per minute.

After the cartons C have been transferred to the carton conveyor 23 and the lower end flaps C have been folded into horizontal position by guides 29, Fig. 1, the flaps C are adapted to be preheated, preparatory to the application of adhesive of the hot-melt type to the flaps C As may be seen in Figs. 8 and 8A, flaps C are adapted to pass through the preheater 200, one being disposed on each side of the carton conveyor 23 to receive the corresponding end flaps C Fig. 8A. Each of the preheater devices 200 comprises a Ushaped eectrical radiant heating element 201 which is supported in a horizontal position, lengthwise of the conveyor and beneath the carton flaps C The carton flaps C are adapted to be held in horizontal position by means of guide rods 202 which extend lengthwise of the conveyor and above the heating elements 201. To concentrate the heat on the carton flaps C there is provided a curved reflector 203 which is disposed beneath the heaters 201 and is supported by a housing 204. The reflector 203 is curved, as shown in Fig. 8A, to redirect the radiant energy from the heater elements 201 and concentrate it on the lower surface of the end flaps C There is also provided an upper reflector plate 205 which is disposed above the carton flaps C and cooperates with the lower reflector 203 and heating elements 201 to form a heating zone for the carton flaps C By preheating the flaps of the cartons, the adhesive to be applied thereto is enabled to penetrate the surface of the flaps more readily due to opening of the pores in the board. After the flaps C have passed through the preheating zone, they are adapted to be adhesively coated by the glue-applying roller 32. The adhesive is of the hot-melt type and is fed from a storage tank ST, Figs. 1 and 2, by way of a pipe 210 to a position A, Fig. 8, between the doctor roll 212 and the adhesive transfer roll 32. The surplus adhesive which passes through the rol s 212 and 32 is permitted to drain into a trough 214, Figs. 1 and 2, from which it is returned to the storage tank ST and recirculated throu h the adhesive-applying system. The adhesive transfer roll 32 is adapted to be driven from a motor 215, Fig. l. The motor 215 is adapted to rotate the roll 32 at slow speed after the carton conveyor 23 has stopped. This prevents the adhesive from setting-up during temporary shut-down periods of the svstem and maintains the roll at uniform temperature. When the conveyor 23 is running, the roll 32 is adapted to be driven from the main drive motor 25 by way of over-running clutches.

' As' may be seen in Fig. 8, the adhesive-applying roll 32 is heated internally. The roll 32 is a hollow tubular member having disposed therein a stationary heating unit comprising a supporting web having a central tubular section 217 from which extend a plurality of arms 218. At the outer ends of the arms 218, there are disposed insulating members 219 which are adapted to support a plura ity of heating elements 220. The heating elements 220 extend around the inner surface of the roller 32 and throughout its entire length to provide a uniform temperature. The roll 32 is adapted to rotate about its'journals 32a, Fig. 8,- while the heating unit within the roll 32 remains stationary; as does the shaft extension 217. A source of electrical power is supplied to the heating elements 220 by way of conductors passing through the shaft extension 217.

From the foregoing description, it will be seen that the preheatersfor the flaps C of the cartons are particularly advantageous since they permit the adhesive to penetrate the fiaps in a minimum amount of time and also prevent the flaps from chilling the adhesive when they are brought in contact with the adhesive-applying roll 32. This enables the carton conveyor to operate at a high rate of speed and, at the same time, provides for a good seal of the carton flaps.

After the flaps C; at the bottom of the cartons have been coated with adhesive, they are folded inwardly, as shown in Fig. 8, by guides 33, and thereafter maintained in folded position while the adhesive sets by the endless belt 35, Fig. 1. The cartons are then moved to the filling zone F of the machine where they are filled, after which the short upper end flaps C are folded inwardly and the long upper end flaps C are folded outwardly into a horizontal plane. The flaps C are adapted to pass through a heating zone similar in construction to the one previously described for flaps C After the flaps C have been preheated, they are adapted to be coated with adhesive by an adhesive-applying device 52, Fig. 2, which includes a heated roller similar to roll 32 described above in detail in connection with Fig. 8. If it isdesired to apply the adhesive to the end flaps of the cartons C in a predetermined pattern, the glue-applying roll 32 may be provided with an exterior construction, as described in copending application Serial No. 366,452, filed Iuly'7, 1953, by Gritfin and Killion, now'U.S. Patent No. 2,873,717.

After the end flaps at the top and bottom of the cartons have been sealed, the cartons'are turned through an angle of so that they will proceed through the remainder of the system inbroadside position. This minimizes the length of the drying conveyor required and positions the cartons which include Van Buren ears C C so that the adhesive on these cars may be reactivated and the ears turned down and sealed against the sides of the cartons as now to be described.

Since the cartons are traveling at a very high rate of speed through the system, it is important that they be positively controlled during their rotation to the broadside position. As may be seen in Figs. 9 and 10, the transfer station T of the machine includes a 6-pronged star wheel 225 comprising a pair of spaced plate members, Fig. 10, secured to a" shaft 226 which is adapted for rotation in a bearing member 227. The star wheel 225 is driven in timed relation with the carton conveyor 23 by meansof the sprocket wheel 230 which rotates with the drum 24 and the sprocket chain 231 which connects the sprocket wheel 230 with a sprocket 233 which is secured to theshaft 226 of'the star wheel 225. As may be seen in. Fig. 9, the cartons C are engaged by one of the spokes of the star wheel 225 before they leave contact with the block 22' which forms one side of the pocket on the conveyor belt 23. It. will be noted in Fig. 9 that the cartons advance in straight-line position until they are beyond the influence of the carton conveyor blocks 22 at which time one of the fingers on the star wheel 225 engages the rear inner corner of each carton and causes the r cartons to be rotated in -a clockwise direction until each zone includes a side plate or" guide 243'- which iscurved and is also provided with an inner surface of Teflon indi-.

cartons C are adapted to be engaged by a top plate 245 which also is lined with Teflon at 246. The top plate 245 is provided with a handle 247 and is hinged at 248 to permit removal of the cartons from the turn-around station. The effect of the pressure of the top plate 245 on the carton C is important in regard to the action of the star wheel 225. If the pressure of the top plate 246 is too great, the star wheel 225 will cut into the carton C as it advances them, thus damaging the cartons. If the pressure of the top plate is too light, the cartons will tilt during advancement and jam the star wheel 225. Thus, in order to control the pressure of the top plate 246 on the cartons C, there is provided an adjustment screw 250, Figs. 9 and 11, which extend through the top plate 246, and is adapted to engage a projection 251 extending from a support 253 alongside the path of the cartons.

The cartons are adapted to be stripped from the star wheel 225 by means of guide structure 254 which is provided with a Teflon face 255, Fig. 11. Similar guide structure 256 is provided for engaging the opposite sides of the carton C. The guide structure 256 is also faced with Teflon 257, Fig. 11. To adapt the turn-around station to handle cartons of various sizes, it will be noted in Fig. 11 that the top plate 245 is adjustable vertically by means of bolts 260 which extend through slots in vertical supports 161. Member 251 is likewise adjustable vertically by means of a bolt 262 which extends through a slot in vertical member 252. The bottom plate 240 is carried by a support 265, the latter being secured by bolts 266 which extend through slots in the'vertical supports 261. v

As may be seen in Fig. 11, the side guides 254 and 256 likewise are adjustable to accommodate cartons of different dimensions. The curved side plate 243 is adjustable by means of the rod 265 which extends through support 266.

The star wheel 225 is adapted to feed the cartons C through the turn-around station T and to push them beneath the top guides 270 into position between the spaced endless conveyor belts 271 of the reactivating conveyor R. As may be seen in Fig. 12, the cartons C have been turned so that their short dimension is lengthwise of their direction of travel and the Van Buren ears C and C-; at the top and bottom of the cartons project horizontally outward from the sidewalls of the carton. These ears C and C, were coated with adhesive at the previously described adhesive-applying stations since the ears C oand Cq are in effect extensions of the corresponding end flaps C and C respectively. Since the hot-melt adhesive sets rapidly, it is necessary to reactivate the adhesive on the ears C and C; before they are sealed to the sidewalls of the cartons C. This is accomplished by means of the electric radiant heater elements 275 which are adapted to be supported adjacent the Van Buren ears C and O; on both sides, and at the top and bottom, of the reactivating conveyor R. Each of the radiant heat ing elements 275 is provided with a reflector 276 which is adapted to direct the heat against the respective ears C and C and additionally to direct the heat against the portions of the sidewalls of the cartons C to which the ears C and C are to be sealed. The preheating of the portions of the sidewalls allows the adhesive to penetrate the board more rapidly, as previously described in connection with the preheating of the end flaps C and C The conveyor belts 271 of the reactivating conveyor preferably are formed from wire mesh, so as to resist the absorption of heat and prevent them from scorching the cartons. The temperature provided by the heaterelements 275 is in the order of 1400 F. This temperature is similar to that provided by the heating members 201 for preheating the endflaps C shown in Fig. 8.

The conveyor belts 271 are driven from sprocket chains 280 which connect the sprocket wheels 281 on pulleys 282 of the reactivating conveyor R. with the pr0cket wheels.

284 carried by the shafts 285 on the drying conveyor-atthe drying station D, Fig. 12. The drying conveyor is driven from achain 290, Fig. l, which is connected to an adjustable feed drive unit 291 of conventional type. By adjusting the wheel 292, the speed of the belts 294 which comprise the drying conveyor may be adjusted in predetermined relation with respect to the speed of the carton conveyor 23.

Each of the drying conveyor belts 294 is formed by a pair of spaced chains 295 which are adapted to pass over pairs of sprocket wheels 296 carried by the shaft 285, Fig. 12. The surfaces of the conveyor belts 294 are formed by a plurality of flights constructed from narrow metal plates 298. The sides of the links of the chains 295 are provided with L-shaped brackets or lugs 300, as shown in Fig. 13, and the flight plates 298 are adapted to be screwed to the brackets, as by screws 301. In order that the flight plates 298 of the drying conveyor belt 294 will apply the proper pressure to the top and bottom ends of the cartons C, the chains 295 are supported by rods 305 which extend lengthwise of the conveyor and are ad:

justable vertically on the side supports or channels 306.

The rods 305 are carried by L-shaped brackets 307 which in turn are secured by bolts 308 which extend through vertical slots in supports 306.

The preferred embodiment for the drying conveyor belt is shown in Fig. 12 and includes the flat metal plates or flights which are attached to the L-shaped brackets 300 carried by the chains 295. These belts are not subject to the disadvantage of fabric or rubber belts. At high speeds, the fabric or rubber belts cause the cartons to tilt during passage therebetween since the thickness of the belt material varies, and thus it is impossible to maintain a uniform spacing between the belts. The chain belts with the metal plates are of accurate dimension, and thus a uniform spacing can be maintained between the two belts 294 and a uniform controlled pressure applied to the end flaps of the cartons. The cartons C will not tilt on the belts 294, and thus there is averted any pile-up or damage to the cartons when they pass through the drying conveyor D.

As may be seen in Fig. 12, when the cartons C leave the reactivating conveyor R, the Van Buren ears C and C will be engaged by the guides 310 and 311, respectively, which press the ears C and C against the preheated sides of the cartons C. As the cartons pass through the drying conveyor, the Van Buren ears C and C are held against the sidewalls of the cartons C by means of pressure-applying devices illustrated in the form of brushes 315. The brushes 315 are made up of nylon bristles and extend lengthwise of the conveyor and on both sides with one pair disposed at the top and one pair near the bottom of the carton to engage the Van Buren ears C and O, at both ends of the cartons. The brushes 315 provide a uinform pressure against the Van Buren ears and thus permit the ears to be sealed tightly against the sides of the cartons C. It is important that the pressure be maintained uniform, since if the pres: sure varies, the ears are permitted to breathe, i.e., the ears, instead of being tightly held against the sides of the cartons, will be permitted to move away from it. This is undesirable, since the ears should be held against the sides of the carton sufliciently long to permit the adhesive to bite into the cardboard and thus obtain an initial set. Once the ears have started to breathe, the adhesive will not set up and the carton ears will be loose. The foregoing action is also true with respect to the end flaps of the cartons, and this is other reason why the chains 295 with the metal plates 298 are preferable over fabric or rubber type belts.

With the hot-melt adhesives, it is necessary to chill the adhesive on the sealed flaps as rapidly as possible in order to cause it to set in the minimum amount of time. To accomplish this, the drying conveyor D is preferably enclosed within a housing 330, the ends of which are pro! vided with openings of-sufiicient area to permit the entry and discharge of the cartons C. The walls of the housing 330 preferably are insulated with heat insulation, such for example, as glass wool. At the top of the housing 330, there is positioned an air-conditioning unit 331 which is connected to the housing 330 by way of a delivery duct 334 and a return duct 335. The air-conditioning unit 331 may be of any conventional type, such for example, as air-cooled or water-cooled, and should have sufficient capacity for controlling the temperature of the air within the drying conveyor D within predetermined limits. With adhesives of the hot-melt type, satisfactory results have been obtained by controlling the tempera ture of the air within the housing 330 to a temperature of approximately 35 F. This temperature chills the adhesive, allowing it to set up rapidly and form a good seal on the flaps and ears of the cartons, but at the same time the temperature is above freezing so as not to form frost on the metal conveyor belts. The flights 298 preferably are formed from a good heat conducting metal, such for example, as aluminum, which will rapidly conduct the heat away from the sealed flaps of the cartons as the cartons move through the conveyor housing 330 and when the flights 298 move out of contact with the cartons at the discharge end of the housing 330, the cold air passing through duct 334- will rapidly chill the flight plates 298 as they return to the opposite end of the conveyor preparatory to engaging another carton and moving with it through the housing 330. Since the Van Buren ears have been reheated for reactivation of the adhesive just prior to entry into the drying conveyor, additional cooling medium may be directed against these ears by means of a pipe 340 having a plurality of openings lengthwise thereof which are adapted to direct an air blast against the bristles of the respective brushes 315. The air which is passed through the pipe 340 preferably is cooled and derived from the air-conditioning unit 331.

While the modification shown in Fig. 12 employing brushes 315 for providing the uniform pressure against the Van Buren cars is preferred, other satisfactory modifications are shown in Figs. 13, 13A and 14. in Figs. 13 and 13A, the flight plates 298 have been raised above the L-shaped lugs 300 and a compression spring member 350 has been inserted between the flight plate 298 and the L-shaped lugs 300 carried by the chains 295.

As may be seen in Fig. 13A, each of the compression spring members 350 includes circular spring elements 350a disposed at opposite ends of member 350 and adapted to engage the respective Van Buren ears O; at the opposite sides of the cartons. While only the bottom conveyor belt is shown in Figs. 13 and 13A, it will of course be understood that both the upper and lower conveyor belts will be provided with the compression spring members 359. When the compression members 350 pass around the sprocket wheels, the circular elements 356a are caused to spread outwardly by a carton C entering therebetween. Once the members 350 are again in the straight-line path at the top or bottom of the conveyor belts, they again force the circular elements 35% tightly toward each other and thus hold the Van Buren ears tightly against the sides of the cartons.

Another modification in which the pressure-applying means for the Van Buren ears is carried by the drying conveyor belts is shown in Fig. 14. In this modification, the flight plates have been removed from the L-shaped brackets 30% supported by the chains 2% and in their place, there is provided a spring-clamping device 360. The side members 366a of the clamping device 360 are biased toward each other, and are adapted to hold the Van Buren ears C against the sides of the carton C. A stop 361 is adapted to prevent the clamping elements 360a from being forced too closely together, to prevent a carton from being placed therebetween. The guide rods305 are adapted to be moved away from each other on the horizontal arms of the supports 307- at each end of the conveyor in order to spread the clamping elements 350a so that the cartons mayenter and be discharged from the conveyor D;

While the drying conveyor D has been described in connection with the use of hot-melt adhesives 0n the flaps of the cartons and thus the air-conditioning unit 331 adapted to supply cold air for cooling the adhesive, it is to be understood that the drying conveyor may also be used in connection with the cold type or water-soluble adhesives. In such applications, the air-conditioning unit 331 is used to supply warm air for drying the water-soluble adhesive.

While the invention has been described in connection with cartons of the type having Van Buren ears, it is, of course, understood that certain of the features of this invention are also applicable to feeding and sealingcartons of other types at high speed. It is to be understood the invention is not limited to the specific arrangements shown and that changes and modifications may be made in the scope of the appended claims.

What is claimed is:

l. A system for feeding folded cartons at high speed from a stack in the flat to a carton conveyor comprising a main drive shaft, a pair of balanced cams continuously driven by said main drive shaft, each of said balanced cams having a cam track, a pair of reciprocable rods each having cam followers adapted for cooperation with said tracks in the respective ones of said cams, a suction device carried by one of said rods, 21 pusher device carried by the other one of said rods, said suction device and said pusher device being adapted for engagement with the front carton of the carton stack and operable in timed relation to remove successive cartons from the stack and transfer them into opened position on the carton conveyor.

2. A system according to claim 1 including valve means for cutting off the suction to said suction device while permitting continued actuation of said suction device into engagement with the cartons in the stack so as to render said suction device ineffective for removal of cartons from the stack.

3. A method of sealing cartons of the type having end flaps and ears comprising the steps of moving cartons along a predetermined path with the flaps and ears thereof in extended horizontal position, heating the flaps and ears while in said horizontal position without interrupting the movement of the cartons so as to raise the temperature of the flaps and ears above ambient and render the surface of the flaps and cars more receptive to adhesive, immediately thereafter applying adhesive to the preheated surfaces of the flaps and ears, folding the flaps against the ends of the cartons to close the cartons, reheating the adhesive coated ears to reactivate the adhesive thereon, and thereafter folding the ears and sealmg them against the sides of the cartons. 4. A system for feeding and sealing cartons comprising a carton conveyor for supporting cartons and moving them along a predetermined path with their end flaps in extended position, means for moving the end flaps of the carton into a horizontal position, means for heatmg the surfaces of the end flaps while maintained in said horizontal position, a heated roller adapted for engagement with said heated end flaps for applying adhesive thereto, said heated roller comprising a tubular member forming the outer surface of said roller, and electrical heating structure disposed within said tubular member, said tubular member being adapted for rotation without rotating said electrical heating structure.

5. A system for feeding and sealing cartons of the type including end flaps and ears comprising a carton conveyor adapted to convey cartons along a predetermined path, means for preheating the end flaps of the cartons to raise the temperature thereof above ambient, means for applying adhesive to the end flaps and ears while at the raised temperature, means for folding the end flaps into sealing engagement at the ends of the cartons while leaving the ears in extended position, and means for reheating the ears to reactivate the'adhesive thereon and thereafter fold them into engagement with the sides of the cartons. r

6. A method of sealing cartons of the type having end flaps and cars which comprises moving the cartons along a predetermined path with their narrower sides presented respectively to like sides of the preceding and following cartons and performing, during movement of each of the cartons all of the steps of applying adhesive to the flaps and ears thereof, folding the flaps into adhesive attachment with one another to close the ends of the carton while leaving the ears on the flaps in extended position, applying pressure to the ends of the carton, turning the carton broadside to the preceding carton, reactivating the adhesive on the ears, folding the ears into adhesive at tachment with the sides of the cartons, and thereafter concurrently applying pressure to the flaps at the ends of the cartons and to the ears at the sides of the cartons while continuing to move the cartons along said predetermined path.

7. A system for feeding and sealing the cartons comprising a conveyor for moving cartons in predetermined spaced relation to each other, and rotatable means for turning said cartons to an angle of 90 for continued movement through said system, said turning means com prising wheel structure having a plurality of spaced projections rotated in timed relation to the movement of said conveyor, each of said projections being adapted to engage a carton and initiate the turning thereof while the carton is still under the influence of said carton conveyor so as to maintain the predetermined spacing between the cartons while they are turned through the an-- gle of 90. 1 8. In a system for feeding and sealing cartons, means for turning the cartons through an angle of 90 comprising rotating structure having a pair of spaced plates, each of said plates having a plurality of arms, one arm. on each of said plates cooperating to engage the side walls of a carton, a support for the bottom of the car-l tons along the side of said rotating structure, guide means carried by said support and adapted to engage the side and top ofsaid cartons in cooperation with said rotating structure in turning the cartons through the angle of 90.

9. Apparatus according to claim 8 wherein said support and said guide structure is provided with an antifriction surface for engaging the carton. 10. Apparatus according to claim 9 wherein said antifriction surface is. formed from afiuorocarbon resin.

11. Apparatus according to claim 8 wherein said guide structure for engaging the top of the cartons comprises a hinged cover member, and means for adjusting the pressure of said cover member against the top of the cartons for controlling the pressure of said arms of said rotatable member on the side walls of the carton during rotation of the. carton. through theangle of 90 N 12. A system, for feeding .and filling cartons of th type including end flaps and ears comprising a carton conveyor adapted to convey cartons along a predetermined path, means for applying adhesive to the end flaps and ears of the cartons while on said carton conveyor, means, for folding the end flaps into engagement at the ends of the cartons while leaving the ears. in extended position, means for rotating said cartons from an angle of 90? and moving said'cartons, between a pair of spaced endless belts engaging the ends of the cartons, means for heating the ears of the cartons to reactivate the adhesive thereon, means for thereafter folding the ears against the sides of the carton, and conveyor means for applying pressure to the end flaps of the carton and to the ears of the carton while directing a drying medium against the surface of the carton to dry the adhesive on the flaps and ears and seal the carton.

13. In a system for sealing cartons having end flaps and cars, a reactivating conveyor for reactivating the una 14 sealed ears on'the closed end flaps of cartons 'compri s= ing a pair of spaced endless belts adapted to engage the closed end'flaps of the cartons while permitting the ears to extend therefrom, heater means arranged along the sides of the endless belts and adjacent the ears of the cartons for heating the ears to reactivate the adhesive thereon, and means for folding the heated ears against the sides of the cartons.

'14. A reactivating conveyor according to claim 13 wherein said endless belts have a construction for resisting the absorption of heat from said heater means so as to prevent scorching of said cartons.

15. A reactivating conveyor according to claim 13 wherein said heater means comprises electrical radiant heaters extending lengthwise of said belts, and reflector means cooperating with said heaters concurrently to reactivate the adhesive on the ears and preheat'the adjacent surface areas of the sides ofthe cartons against which the ears are adapted to be folded.

16. A system for feeding and sealing cartons comprising a carton conveyor for supporting cartons and moving them along a predetermined path with their flaps in extended position, a heated roller for applying adhesive to the end flaps of the cartons while moved along by said conveyor, and means for driving said heated roller independly of movement of said conveyor so as to maintain the roll at uniform temperature and prevent the adhesive from 'setting-up during temporary shutdown periods of said system.

17. A system according to claim 16 wherein said heated roller comprises a hollow tubular member, and a plurality of electrical heating elements extending around the inner surface of said tubular member and throughout its length to uniformly heat the exterior adhesive-applying surface of said tubular member.

18. In a system for feeding cartons, the improvement comprising a carton magazine, cyclically movable means for supporting a stack of folded cartons in the fiat on their edge in said magazine, said cyclically movable means including at least one drive chain extending the length of said magazine, guide structure extending along the side of said magazine, trolley structure movable along said guide structure, a pusher device pivoted to said trolley structure and movable into and out of locking engagement with said drive chain of said cyclically movable means, said pusher device cooperating with said drive chain for applying pressure to therear end of the stack of folded cartons to cyclically advance the stack along said carton magazine and said pusher being movable out of engagement with said drive chain to add cartons to the stack in said magazine.

19. In a system for sealing cartons, the improvement of a drying conveyor for closed cartons comprising a pair of endless belts adapted to receive cartons therebetween and transport them through a drying zone, an insulated housing surrounding said drying zone, means for controlling the pressure of said belts on the ends of the cartons to hold the flaps in sealing engagement, means for directing a drying fluid of predetermined temperature into said drying zone for controlling the temperature of the cartons as they pass through said drying zone, and means for controlling the temperature of said drying fluid.

20. A drying conveyor according to claim 19 wherein said belts com-prise spaced endless chains, and a plurality of fiat metal plates carried by said chains, and said means for controlling the pressure comprises guide structure for said chains extending lengthwise of said conveyor to maintain a uniform spacing between said belts and to receive the cartons.

21. In a system for sealing cartons of the type including flaps and ears, the improvement of a drying conveyor for closed cartons comprising a pair of endless belts adapted to receive cartons therebetweenand transport them through a drying zone, means for controlling the pressure of said belts on the ends of the cartons to hold the flaps in sealing engagement, means within said drying zone for applying a uniform pressure to the carton ears to hold them in sealing engagement with the sides of the carton during transport of the carton through said drying zone, and means for directing a drying fluid of predetermined temperature into said drying zone for controlling the temperature of the cartons as they pass through said drying zone.

22. A drying conveyor according to claim 21 wherein said means for applying pressure to the ears on the cartons comprises brush means having bristles engaging the carton ears.

23. A drying conveyor according to claim 22 including means for directing a blast of drying fluid against said brush means and the carton ears to assist in drying the ears.

24. A drying conveyor according to claim 21 wherein said means for applying pressure to the carton ears comprises spring-biased means carried by said pair of endless belts and engaging the ears to clamp them against the sides of the cartons.

25. A system for feeding and sealing folded cartons at high speed from a stack in the flat, comprising carton conveyor means, means for feeding a stack of flattened cartons to bring the front end of the stack against an abutment adjacent said carton conveyor means preparatory to transfer of a carton thereto, means for transferring the carton at the front end of the stack to said carton conveyor means, pressure means cyclically movable with said carton transfer means for applying a predetermined pressure against the front end of the stack, said last-named means being effective during removal of the cartons from the stack to prevent increase in compression on the cartons in the stack above said predetermined pressure, means to render said cyclically movable means ineffective when said conveyor is moving but cartons are not being removed from the stack so as to maintain constant the then-existing pressure on the cartons in the stack, means for opening the cartons so that their end flaps and ears project therefrom as they are conveyed along a predetermined path and at a predetermined spacing by said conveyor means, means for preheating the end flaps of the cartons to raise the temperature thereof above ambient, means for applying adhesive to the end flaps and ears while at the raised temperature, means for folding the end flaps into sealing engagement at the ends of the carton while leaving the ears in extended position, rotatable means for turning the cartons through an angle of 90 for continued movement through said system with their short dimension lengthwise of said conveyor means, to permit reactivation and folding of the ears on the cartons, said rotatable means comprising wheel structure having a plurality of spaced projections rotated in timed relation to the movement of said conveyor means, each of said projections being adapted to engage a carton and initiate the turning thereof while the carton is under the influence of said carton conveyor means so as to maintain the predetermined spacing between the cartons while they are turned through the angle of 90, means for reheating, the ears to reactivate the adhesive thereon and thereafter fold them into engagement with the sides of the cartons as they continue to be conveyed through said system, brush means disposed along said conveyor means and having bristles engaging the carton ears for applying pressure to the ears on the cartons, and means for directing a blast of drying fluid against said brush means and the carton ears to assist in drying the ears for completion of] the sealing of the cartons.

26. A system for feeding folded cartons at high speed from a stack in the flat to a carton conveyor comprising means for feeding a stack of flattened cartons to bring the front end of the stack against an abutment adjacent the carton conveyor preparatory to transfer of a carton thereto, a main drive shaft, an eccentric cam driven continuously from said main drive shaft, a onecycle clutch for operating said stack-feeding means, and cyclically movable means for applying a predetermined pressure against the front end of the stack effective durinf normal operation of said system to prevent increase in compression on the cartons in the stack above said predetermined pressure, said cyclically movable means for applying a predetermined pressure against the front end of the stack of cartons comprising control means normally adapted to engage the front end of the stack, spring means for biasing said control means against said stack and into engagement with an arm on said one-cycle clutch, said spring means being adapted to apply a predetermined pressure against said stack and adapted to move said arm against the surface of said eccentric cam until the pressure on cartons in said stack exceeds the predetermined pressure of said spring biasing means.

27. A system according to claim 26 including means to render said cyclically movable means ineffective when cartons are not being removed from the stack so as to maintain constant the then existing pressure on the cartons in the stack.

28. A system according to claim 27 wherein said means to render said cyclically movable means ineffective comprises a solenoid including a movable element which is connected to said arm of said one-cycle clutch, said solenoid being selectively energized to hold said arm of said one-cycle clutch out of engagement with the surface of said eccentric cam and thus prevent said onecycle clutch from further advancing said stack-feeding means to maintain the pressure of the cartons in the stack at the then existing value.

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